The Obama administration is rewriting new rules on medical privacy after an outpouring of criticism from consumer groups and members of Congress who say the rules do not adequately protect the rights of patients. Democratic lawmakers and a few Republicans have denounced the rules, saying they fall short of offering patients the fullest protections possible. Hospitals and insurance companies, seeking to maintain greater control over patient notification, generally support the rules. The White House finds itself caught in the middle. The rules specify when doctors, hospitals and insurers must tell patients about the improper use or disclosure of information in their medical records. Such breaches appear to have become more frequent, with the growing use of health information technology, social media and the Internet.